Search results for "Artificial seawater"
showing 7 items of 17 documents
Speciation of polyelectrolytes in natural fluids Protonation and interaction of polymethacrylates with major components of seawater.
2002
Acid–base properties of two sodium polymethacrylates (W= 4000 and 5400 Da) were studied potentiometrically in aqueous solution at 25 °C. Measurements were made in different salt solutions: LiCl 0.1–1.5, NaCl 0.1–2, KCl 0.1–2, Et4NI 0.1–0.75 mol l − 1 , and in artificial seawater in the salinity range 10 S 45. Protonation data were analysed by two different models and the dependence of the relative parameters on ionic strength were calculated. Measurements performed in interacting media (alkali metal chlorides and artificial seawater) were interpreted in terms of complex formation, and the relative formation parameters are reported. Previous data on the interaction of a higher molecular weig…
Speciation of Low Molecular Weight Carboxylic Ligands in Natural Fluids: Protonation Constants and Association with Major Components of Seawater of O…
1999
Abstract The interaction of oxydiacetate and citrate with the major components of seawater has been studied potentiometrically, at 25°C, in an artificial seawater (containing Na+, K+, Ca2+, Mg2+, Cl− and SO42−) at different salinities (5–45‰). Apparent protonation constants were calculated, from potentiometric data, and estimated, using an appropriate complex formation model. Formation constants of complexes formed by oxydiacetate and citrate and the cation of seawater (the inorganic content of seawater being considered as a single 1 : 1 salt) were determined. The single salt approximation for the major inorganic components of seawater, which is a good tool in estimating the mean strength o…
Equilibrium studies in natural fluids: interactions of -PO43−, -P2O74−and -P3O105−with the major constituents of sea water
1998
AbstractThe interaction of PiO(i+2)−(3i+1) (i = 1,2,3) with the major components of seawater has been studied potentiometrically, at 25°C, in an artificial seawater (Na+, K, Ca2+, Mg2+, Cl− and SO42−) at different salinities (5—45%o). Apparent protonation constants have been calculated, from potentiometric data, and estimated, using an appropriate complex formation model. Formation constants of complexes formed by phosphates and the cation of seawater (the inorganic content of seawater being considered as a single 1:1 salt) have been determined. The comparison between experimental and estimated results showed that a suitable complexation model can be used with a fairly good accuracy in pred…
Modelling of natural synthetic polyelectrolyte interactions in natural waters by using SIT, Pitzer and Ion Pairing approaches
2006
Abstract In this paper SIT and Pitzer models are used for the first time to describe the interactions of natural and synthetic polyelectrolytes in natural waters. Measurements were made potentiometrically at 25 °C in single electrolyte media, such as Et 4 NI and NaCl (for fulvic acid 0.1 − 1 S single salt ” BA, with cation B and anion A representing all the major cations (Na + , K + , Mg 2+ , Ca 2+ ) and anions (Cl − , SO 4 2− ) in natural sea water, respectively. The ion pair formation model was also applied to fulvate and alginate in artificial sea water by examining the interaction of polyanions with the single sea water cation. Results were compared with those obtained from previous sp…
Speciation of trialkyltin(IV) cations in natural fluids
2004
The hydrolysis of (CH(3))(3)Sn(+), (C(2)H(5))(3)Sn(+) and (C(3)H(7))(3)Sn(+) has been studied in a Synthetic Seawater (SSW) ionic medium simulating the major composition of natural seawater, at different salinities (5 less than or equal to S less than or equal to 45), and at t = 25 degreesC. Interactions with anionic components of SSW, considered as single sea salt, are determined by means of a complex formation model. By potentiometric measurements (ISE-H(+) and ISE-F(-) electrodes), the model has been extended to also consider interactions of organotins with carbonate and fluoride ions, which are other important components of seawater. Literature and new values of hydrolysis constants in …
Influence of aquatic microbiota on the survival in water of the human and eel pathogen Vibrio vulnificus serovar E
2004
Summary The eel and human pathogen Vibrio vulnificus serovar E (biotype 2) is seldom isolated from natural waters, although it can survive in sterilized artificial seawater microcosms for years. The main objective of the present study was to investigate whether aquatic microbiota can limit its survival and recovery from water samples. A set of preliminary experiments of survival in microcosms containing natural seawater and water from eel farms showed that the persistence of this pathogen was mainly controlled by grazing, and secondarily by bacterial competition. The bacte- rial competition was further analysed in artificial seawater microcosms co-inoculated with selected virulent serovar E…
Regulation of motility of cells from marine sponges by calcium ions
1996
Sponges are known not to contain muscle and nerve cells. Since sponge cells are characterized by high motility we determined the effect of intracellular calcium ion concentration ([Ca2+]i) on their motility. Addition of the Ca2+ ionophore ionomycin to dissociated cells from the marine sponge Suberites domuncula caused in Ca(2+)-containing artificial seawater (ASW) an increase in motility from 0.2 micron/min (absence of the ionophore) to 3.7 microns/min (presence of ionomycin). When the experiments were performed in Ca(2+)-free medium, no effect of ionomycin could be observed. In parallel experiments the changes of [Ca2+]i using the dye Fura-2 were measured. The experiments revealed that ion…